Finding the potential of karst water resources in Birjand city using hierarchical analysis model and geographic information system

Exploration of underground water sources as one of the ways to provide drinking water in the world is necessary and inevitable, considering the ever-increasing need of the world for water. The water crisis in Iran, especially in hot and dry cities, has now become a serious challenge. The high salinity and degree of hardness of water and water shortage in Birjand city will remind the officials related to water resources more and more about the solution of alternative water sources in the near future. Knowing the effective factors in finding the potential of karst water resources has a special place in the field of land management studies. The purpose of this research is to find the potential of karst water resources in Birjand city in South Khorasan province using AHP model. In this research, with the hierarchical analysis model, lithology information layers, distance from fault, slope, direction of slope, height, distance from waterway, distance from fault and land use were considered as factor maps. Also, in order to extract the karst water resource potential model, the shape files were called in the GIS10.3 ARC software environment. Different layers of information were classified as criteria maps by applying expert opinions and field observations. Finally, according to the obtained weight, the potential measurement map of karst water sources in Birjand city was obtained. The results showed that of the total area of ​​Birjand city, 26.40% is in the very low developed class, 27.58% in the low developed class, 23.86% in the middle class, 15.75% in the high developed class and 40.40% 6% is too much in the development class. Therefore, according to the judgment of karst experts and experts, the lithology factor of the area with a value of 0.41 has the highest weight and the most important factor controlling the potential of karst water resource development in the studied area, and the land use factor with a value of 0.017 has the lowest weight. assigned The results show that the lithological factors, the distance from the fault and the distance from the waterway have played the most important role in the current development of karst water resources in this city.